1. Field of the Invention
The present invention relates to a rotary connector which is mounted on a steering device of an automobile or the like and is used as electric connection means between electric apparatuses such as a steering heater and an air bag system mounted on a car body of an automobile.
2. Description of the Related Art
To explain a drawing which shows a conventional rotary connector, FIG. 6 is a plan view showing the conventional rotary connector.
The rotary connector 60 is incorporated in a steering apparatus of an automobile or the like (not shown in the drawing) and is employed as electrical connection means for a steering heater circuit mounted in a steering wheel, an airbag circuit, a horn circuit and other switching circuits. The rotary connector 60 is basically comprised of a pair of a stationary housing 61 and a movable housing 62, both being disposed coaxially and connected together so as to be rotatable relative to each other, a flexible cable (not shown in the drawing) housed in an annular cable accommodating portion (not shown in the drawing) formed between a pair of these stationary and movable housings 61, 62 such that a flexible cable can be wound and unwound in the space, and a first and a second single lead blocks 63, 64 which are respectively connected to both ends of the flexible cable.
The flexible cable (not shown in the drawing) is constructed such that a plurality of (for example, six) of conductors made of an extremely thin strip-like copper foil or the like, each conductor being interposed between two sheets of insulating films as a strip-like base film, are disposed in parallel with each other and stuck to the insulating films.
The rotary connector 60 having such a basic construction is further fabricated as follows: fix the stationary housing 61 to a car body (not shown in the drawing) while fixing the movable housing 62 to a steering wheel member (not shown in the drawing); and further connect both ends of the flexible cable to associated electric devices on the sides of the car body and the steering wheel member via respective first and second lead blocks 63, 64 arranged at the stationary side and the movable side; thus realizing electrical connection means for a heater circuit device for steering apparatus, a vehicle-mounting airbag system and a horn circuit.
The stationary housing 61 made of synthetic resin material includes a cylindrical outer cylinder 65, a bottom wall 66 which is formed on an end of the outer cylinder 65, and one first accommodating portion 67 which is projected outwardly from a position in the vicinity of an outer peripheral end of the bottom wall 66.
On the other hand, the movable housing 62 made of synthetic resin material includes a cylindrical inner cylinder 68, an upper wall 69 which is formed on an end of the inner cylinder 68, and one second accommodating portion 70 which is projected outwardly from a position in the vicinity of an outer peripheral end of the upper wall 69.
The first lead block 63 includes a holding member 63a made of synthetic resin material and a plurality (for example, six) of terminals 63b made of metal material which are formed in the holding member 63a by insert molding. These terminals 63b are provided with connection terminal portions 63c which are projected outwardly from the holding member 63a. These connection terminals 63c are extended outwardly in a straight manner from proximal portions thereof which are connected to the holding members 63a. Further, these connection terminals 63c are arranged in parallel on a straight line S2 equidistantly in a row.
The first lead block 63 is held in the first accommodating portion 67 of the stationary housing 61 and one end of one (1 piece) flexible cable (not shown in the drawing) is electrically and mechanically connected to each terminal 63b. 
The second lead block 64 includes a holding member 64a made of synthetic resin material and a plurality (for example, six) of terminals 64b made of metal material which are formed in the holding member 64a by insert molding. These terminals 64b are provided with connection terminal portions 64c which are projected outwardly from the holding member 64a. These connection terminal portions 64c are extended outwardly in a straight manner from proximal portions thereof which are connected to the holding members 64a. Further, these connection terminals 64c are arranged in parallel on a straight line S3 equidistantly in a row.
The second lead block 64 is held in the second accommodating portion 70 of the movable housing 62 and the other end of one (1 piece) flexible cable (not shown in the drawing) which is connected to the terminal 63b is electrically and mechanically connected to each terminal 64b. 
Then, with respect to respective terminals 63b, 64b of the above mentioned first and second lead blocks 63, 64, two connectors consisting of, for example, a first connector for a steering heater circuit (not shown in the drawing) and a second connector for an air bag circuit and a horn circuit (not shown in the drawing) are respectively inserted into the first and the second accommodating portion 67, 70 thus establishing the electrical connections.
However, in the above mentioned conventional rotary connector, each connection terminal portion is configured such that two connectors are respectively inserted into one lead block which is extended along one straight line in a straight manner and hence, there arises a problem that these two connectors are erroneously inserted in such a manner that the left position is mistaken for the right position.
Accordingly, it is an object of the present invention to solve the above mentioned problems and to provide a rotary connector which can securely connect respective connectors to given connecting terminal portions when two connectors are respectively inserted into one lead block.
According to the rotary connector of first aspect of the present invention, the rotary connector substantially comprises a stationary housing on which a first lead block is mounted, a movable housing on which a second lead block is mounted and is rotatably mounted with respect to the stationary housing, and a flexible cable which is accommodated inside an accommodating portion formed between the stationary housing and the movable housing, wherein at least one of the first and second lead blocks includes a holding member and a plurality of terminals having connection terminal portions which are projected outwardly from the holding member, respective terminal portions of the flexible cable are connected to a plurality of terminals, a plurality of terminals are formed of at least two, that is, first and second groups of terminals, and, at different positions on first and second straight lines which are placed in parallel with each other with a given distance between them, distal ends of respective connection terminal portions of the first and second groups of terminals are arranged in parallel to each other.
Due to such a constitution, when two connectors are respectively inserted into one lead block, respective connectors can be securely connected to given connection terminal portions.
According to the rotary connector of a second aspect of the present invention, respective proximal portions of respective connection terminal portions connected with the holding member are arranged in parallel on the straight lines, the bends are formed on respective connection terminal portions of the first group of terminals and respective connection terminal portions of the second group of terminals are formed in a straight manner.
Due to such a constitution, by providing the bends to respective connection terminal portions of the first group of terminals, the positions of the first and second groups of terminals can be easily made different from each other so that the rotary connector can be provided at a low cost.
Further, according to the rotary connector of a third aspect of the present invention, the second lead block includes the first and the second groups of terminals having the connection terminal portions which are arranged in parallel at different positions on the first and second straight lines.
Due to such a constitution, by providing the connection terminal portions to the movable housing at which connectors are connected by insertion and disconnected by pulling frequently, it is possible to provide the rotary connector which can securely connect the connectors to the first and the second groups of terminals.
Further, according to the rotary connector of a fourth aspect of the present invention, the rotary connector includes two connectors which are respectively connected to the first and the second groups of terminals, and a guide which guides the insertion of the connector is formed on the movable housing.
Due to such a constitution, respective connectors to be inserted can be securely guided by the guide and hence, it is possible to provide the rotary connector with no erroneous insertion of respective connectors.
Further, according to the rotary connector of a fifth aspect of the present invention, distances between positions of the first and the second straight lines on which the respective connection terminal portions are formed and a center line of the guide parallel to the first and second straight lines are set different from each other.
Due to such a constitution, it is possible to provide the rotary connector with no erroneous insertion of respective connectors and with the reliable connection.
Further, according to the rotary connector of a sixth aspect of the present invention, the rotary connector includes two pieces of the first lead blocks which are mounted on the stationary housing and one piece of the second lead block which is mounted on the movable housing, ends of the flexible cable which are connected to the first group of terminals of the second lead block are connected to the terminals of one first lead block out of two lead blocks, and ends of the flexible cable which are connected to the second group of terminals are connected to the terminals of the other first lead block out of two lead blocks.
Due to such a constitution, by mounting two pieces of the first lead blocks to the stationary housing, it is possible to provide a rotary connector which can securely connect separate connectors which are connected to different electric apparatuses to the first lead block.